The Achilles tendon is the longest and most powerful tendon in the human body, measuring approximately 15 cm in length and capable of withstanding a force of 7,000 Newtons. However, during more strenuous sports activities, the Achilles tendon can be subjected to forces up to seven times the body’s weight. In addition, the Achilles tendon can be subjected to greater stress due to the movement of the subtalar joint and the excessive rotation of the foot. The Achilles tendon is a relatively ischemic area within 2-6 cm from the Achilles stop, and the circumference of the Achilles tendon is the thinnest at 4 cm from the stop, making this area the most susceptible to injury. It is the intrinsic cause of non-stop Achilles tendinitis. The most common external cause is inflammation of the peritendinous tissue and degeneration and partial rupture of the Achilles tendon itself after excessive stress and repeated minor injuries. Astrom believes that histopathological changes in the Achilles tendon are not related to exercise and that exercise only exacerbates the symptoms of Achilles tendinitis, but is not the cause. Factors associated with Achilles tendonitis include age-related reduction in blood flow and tissue elasticity, muscle weakness and imbalance, poor limb force lines, incorrect training, inappropriate shoe wear, and the effects of quinolones, hormones, and other medications. (I) Staging Achilles tendinitis is divided into three stages: Stage 1: normal Achilles tendon itself, peritendinous tissue inflammation, peritendinitis; Stage 2: peritendinitis and degeneration of Achilles tendon, manifested by calcification, nodular hyperplasia and loss of normal luster within the tendon; Stage 3: rupture of tendon fibers. (B) Clinical manifestations and diagnosis Non-stop Achilles tendinitis occurs mostly in male athletes aged 35 to 45 years old, and can also occur in the general population of non-athletes. There is pain and localized swelling in the posterior part of the heel, 2-6 cm from the Achilles tendon stop. In the early stages of Achilles tendinitis, pain is felt in the Achilles tendon area when walking or moving around a lot. When the disease worsens, the Achilles tendon may become stiff in the morning and pain may occur at rest. Limping may occur. The patient should be asked about the type and amount of exercise, the nature and extent of pain, previous treatment, and the use of systemic and local hormones. Examination reveals swelling of the Achilles tendon over the Achilles tendon stop and increased localized pain in passive dorsiflexion of the ankle joint. Dorsal extension of the ankle joint may be limited. However, some patients may have increased dorsiflexion of the ankle joint due to lengthening of the Achilles tendon. The pain is localized when the thumb and index finger are squeezed along the inner and outer side of the Achilles tendon. Thickening or nodularity of the Achilles tendon may be palpable. In patients with pure periarthritis, the Achilles tendon pressure point remains the same during ankle extension and flexion, while in patients with partial rupture of the Achilles tendon and Achilles tendonitis, the pressure point changes with ankle extension and flexion, which is also known as the painful arc of the Achilles tendon. The foot should also be examined for inversion and valgus deformity and high arch or flatfoot deformity. X-rays may show swelling of the surrounding soft tissues, and MRI may show the extent of degeneration of the Achilles tendon. According to the duration of the disease, Achilles tendonitis can be divided into 3 stages: 1, acute stage, the duration of the disease is less than 2 weeks. 2, subacute stage, the duration of the disease is 3-6 weeks. 3, chronic stage, the duration of the disease is more than 6 weeks. (C) Treatment 1. Non-surgical treatment (1) Reduce activity. Curvin and Stanish proposed a method of training the Achilles tendon in 1980: the front half of the affected foot stands on a step and the healthy limb is lifted and suspended. The knee joint is flexed and straightened. Fifteen flexion-extension exercises were performed twice daily. Continue for 12 weeks. Patients with Achilles tendonitis may experience localized pain at the beginning and during the exercise. You can continue the exercise. If there is no pain, you can increase the body load, such as carrying heavy objects, to achieve sufficient load to produce pain; (4) braces, orthopedic shoes to correct the poor force line of the foot. (5) Non-steroidal anti-inflammatory pain medication; (6) Injection of hormonal drugs around the Achilles tendon. However, care should be taken not to inject into the tendon parenchyma to avoid affecting the collagen synthesis in the Achilles tendon, affecting the healing and the occurrence of Achilles tendon rupture. 2.Surgical treatment Non-surgical treatment for more than 6 months still does not reduce the symptoms, surgery can be taken. About 25% of the patients are treated surgically. Older age, longer history and recurrence of symptoms are common reasons for surgical treatment. The inflammatory peritendinous tissue and the degenerated Achilles tendon are removed, and small Achilles defects can be sutured directly. Larger defects that cannot be sutured directly need to be repaired with other tissues. The authors used a low-temperature plasma surgical system to treat non-stop Achilles tendinitis with good recent results. A special plasma needle is used to make holes on the surface of the tendon, one hole for each 5 mm or so. The depth is approximately 10 mm.